@nomiclabs/buidler-waffle

buidler-waffle

Buidler plugin for integration with Waffle.

What

You can use this plugin to build smart contract tests using Waffle in Buidler, taking advantage of both.

This plugin adds a Waffle-compatible provider to the Buidler Runtime Environment, and automatically initializes the Waffle Chai matchers.

Installation

npm install --save-dev @nomiclabs/buidler-waffle ethereum-waffle @nomiclabs/buidler-ethers ethers@^4.0.23

And add the following statement to your buidler.config.js:

usePlugin("@nomiclabs/buidler-waffle");

Tasks

This plugin creates no additional tasks.

Environment extensions

This plugin adds a waffle object to the Buidler Runtime Environment. This object has a single property, the Waffle mock provider.

waffle: {
  provider: JsonRpcProvider;
}

This plugin depends on @nomiclabs/buidler-ethers, so it also injects an ethers object into the BRE, which is documented here.

Usage

Once installed, you can build your tests just like in Waffle. The only difference is that you must use waffle.provider instead of createMockProvider().

Note that by default, Buidler save its compilation output into artifacts/ instead of build/. You can either use that directory in your tests, or customize your Buidler config.

TypeScript support

This plugin supports TypeScript by following these steps:

1. Add these to your tsconfig.json's files array: 1.1. "node_modules/@nomiclabs/buidler-ethers/src/type-extensions.d.ts" 1.2. "node_modules/@nomiclabs/buidler-waffle/src/type-extensions.d.ts"

2. Install this packages: npm install --save-dev @types/mocha @types/chai

We also recommend enabling resolveJsonModule in your tsconfig.json, as it's common to import JSON files directly when using Waffle.

There's no need to import the Waffle's solidity Chai matchers. They are automatically imported and initialized by this plugin, including its types.